OBJECTIVE

To analyze significance of laser fluorescence diagnosis for assessment of ischemic, radiofrequency and reperfusion myocardial injury under cardioplegia.

MATERIAL AND METHODS

The study included 15 patients who underwent cardiac surgery under cardiopulmonary bypass and pharmacological cold cardioplegia. Laser fluorescence diagnosis was used for on-line monitoring of the myocardial functional state. We assessed various biological substances including collagen, elastin, reduced form of nicotinamide adenine dinucleotide (NADH), pyridoxine, flavins, lipofuscin. Fluorescence contrast coefficient was used to quantify the fluorescence of myocardial tissue. Fluorescence was evaluated at 4 points: before aortic occlusion, after aortic occlusion and cardioplegia, before aortic clamp release, after weaning from CPB.

RESULTS

Induced fluorescence of pyridoxine, collagen, flavins and lipofuscin was similar at all study points. We have found significant correlation of elastin fluorescence and time of myocardial ischemia and reperfusion. Fluorescence contrast coefficient in the intact myocardium was increased after aortic cross-clamping under cardioplegia and before aortic clamp release compared to its level before aortic occlusion. Significant results were obtained for NADH as a marker of «fast» myocardial damage during radiofrequency exposure under preserved coronary blood flow. Before aortic occlusion, NADH values were significantly different (p=0.03) in the intact myocardium and in the myocardium after radiofrequency transmural damage.

CONCLUSIONS

Laser fluorescence diagnosis in cardiac surgery ensures on-line analysis of the markers of slow (ischemic) and fast (radiofrequency) myocardial damage. Thus, laser fluorescence technique can be used for rapid diagnosis of myocardial injury.